import crypto from 'node:crypto'
import type { MessageValue, PromiseResponseWrapper } from '../utility-types'
-import { EMPTY_FUNCTION } from '../utils'
+import {
+ DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS,
+ EMPTY_FUNCTION,
+ median
+} from '../utils'
import { KillBehaviors, isKillBehavior } from '../worker/worker-options'
-import type { PoolOptions } from './pool'
+import {
+ PoolEvents,
+ type IPool,
+ type PoolOptions,
+ type TasksQueueOptions,
+ PoolType
+} from './pool'
import { PoolEmitter } from './pool'
-import type { IPoolInternal, TasksUsage, WorkerType } from './pool-internal'
-import { PoolType } from './pool-internal'
-import type { IPoolWorker } from './pool-worker'
+import type { IWorker, Task, TasksUsage, WorkerNode } from './worker'
import {
WorkerChoiceStrategies,
- type WorkerChoiceStrategy
+ type WorkerChoiceStrategy,
+ type WorkerChoiceStrategyOptions
} from './selection-strategies/selection-strategies-types'
import { WorkerChoiceStrategyContext } from './selection-strategies/worker-choice-strategy-context'
+import { CircularArray } from '../circular-array'
/**
* Base class that implements some shared logic for all poolifier pools.
*
* @typeParam Worker - Type of worker which manages this pool.
* @typeParam Data - Type of data sent to the worker. This can only be serializable data.
- * @typeParam Response - Type of response of execution. This can only be serializable data.
+ * @typeParam Response - Type of execution response. This can only be serializable data.
*/
export abstract class AbstractPool<
- Worker extends IPoolWorker,
+ Worker extends IWorker,
Data = unknown,
Response = unknown
-> implements IPoolInternal<Worker, Data, Response> {
- /** {@inheritDoc} */
- public readonly workers: Array<WorkerType<Worker>> = []
+> implements IPool<Worker, Data, Response> {
+ /** @inheritDoc */
+ public readonly workerNodes: Array<WorkerNode<Worker, Data>> = []
- /** {@inheritDoc} */
+ /** @inheritDoc */
public readonly emitter?: PoolEmitter
/**
- * The promise response map.
+ * The execution response promise map.
*
* - `key`: The message id of each submitted task.
- * - `value`: An object that contains the worker, the promise resolve and reject callbacks.
+ * - `value`: An object that contains the worker, the execution response promise resolve and reject callbacks.
*
- * When we receive a message from the worker we get a map entry with the promise resolve/reject bound to the message.
+ * When we receive a message from the worker, we get a map entry with the promise resolve/reject bound to the message id.
*/
protected promiseResponseMap: Map<
string,
> = new Map<string, PromiseResponseWrapper<Worker, Response>>()
/**
- * Worker choice strategy instance implementing the worker choice algorithm.
+ * Worker choice strategy context referencing a worker choice algorithm implementation.
*
- * Default to a strategy implementing a round robin algorithm.
+ * Default to a round robin algorithm.
*/
protected workerChoiceStrategyContext: WorkerChoiceStrategyContext<
Worker,
* Constructs a new poolifier pool.
*
* @param numberOfWorkers - Number of workers that this pool should manage.
- * @param filePath - Path to the worker-file.
+ * @param filePath - Path to the worker file.
* @param opts - Options for the pool.
*/
public constructor (
this.checkFilePath(this.filePath)
this.checkPoolOptions(this.opts)
- this.chooseWorker.bind(this)
- this.internalExecute.bind(this)
- this.checkAndEmitBusy.bind(this)
- this.sendToWorker.bind(this)
+ this.chooseWorkerNode.bind(this)
+ this.executeTask.bind(this)
+ this.enqueueTask.bind(this)
+ this.checkAndEmitEvents.bind(this)
this.setupHook()
Response
>(
this,
- () => {
- const createdWorker = this.createAndSetupWorker()
- this.registerWorkerMessageListener(createdWorker, message => {
- if (
- isKillBehavior(KillBehaviors.HARD, message.kill) ||
- this.getWorkerTasksUsage(createdWorker)?.running === 0
- ) {
- // Kill received from the worker, means that no new tasks are submitted to that worker for a while ( > maxInactiveTime)
- void this.destroyWorker(createdWorker)
- }
- })
- return this.getWorkerKey(createdWorker)
- },
- this.opts.workerChoiceStrategy
+ this.opts.workerChoiceStrategy,
+ this.opts.workerChoiceStrategyOptions
)
}
private checkPoolOptions (opts: PoolOptions<Worker>): void {
this.opts.workerChoiceStrategy =
opts.workerChoiceStrategy ?? WorkerChoiceStrategies.ROUND_ROBIN
+ this.checkValidWorkerChoiceStrategy(this.opts.workerChoiceStrategy)
+ this.opts.workerChoiceStrategyOptions =
+ opts.workerChoiceStrategyOptions ?? DEFAULT_WORKER_CHOICE_STRATEGY_OPTIONS
this.opts.enableEvents = opts.enableEvents ?? true
+ this.opts.enableTasksQueue = opts.enableTasksQueue ?? false
+ if (this.opts.enableTasksQueue) {
+ this.checkValidTasksQueueOptions(
+ opts.tasksQueueOptions as TasksQueueOptions
+ )
+ this.opts.tasksQueueOptions = this.buildTasksQueueOptions(
+ opts.tasksQueueOptions as TasksQueueOptions
+ )
+ }
}
- /** {@inheritDoc} */
+ private checkValidWorkerChoiceStrategy (
+ workerChoiceStrategy: WorkerChoiceStrategy
+ ): void {
+ if (!Object.values(WorkerChoiceStrategies).includes(workerChoiceStrategy)) {
+ throw new Error(
+ `Invalid worker choice strategy '${workerChoiceStrategy}'`
+ )
+ }
+ }
+
+ private checkValidTasksQueueOptions (
+ tasksQueueOptions: TasksQueueOptions
+ ): void {
+ if ((tasksQueueOptions?.concurrency as number) <= 0) {
+ throw new Error(
+ `Invalid worker tasks concurrency '${
+ tasksQueueOptions.concurrency as number
+ }'`
+ )
+ }
+ }
+
+ /** @inheritDoc */
public abstract get type (): PoolType
/**
- * Number of tasks concurrently running.
+ * Number of tasks running in the pool.
*/
private get numberOfRunningTasks (): number {
- return this.promiseResponseMap.size
+ return this.workerNodes.reduce(
+ (accumulator, workerNode) => accumulator + workerNode.tasksUsage.running,
+ 0
+ )
+ }
+
+ /**
+ * Number of tasks queued in the pool.
+ */
+ private get numberOfQueuedTasks (): number {
+ if (this.opts.enableTasksQueue === false) {
+ return 0
+ }
+ return this.workerNodes.reduce(
+ (accumulator, workerNode) => accumulator + workerNode.tasksQueue.length,
+ 0
+ )
}
/**
- * Gets the given worker key.
+ * Gets the given worker its worker node key.
*
* @param worker - The worker.
- * @returns The worker key if the worker is found in the pool, `-1` otherwise.
+ * @returns The worker node key if the worker is found in the pool worker nodes, `-1` otherwise.
*/
- private getWorkerKey (worker: Worker): number {
- return this.workers.findIndex(workerItem => workerItem.worker === worker)
+ private getWorkerNodeKey (worker: Worker): number {
+ return this.workerNodes.findIndex(
+ workerNode => workerNode.worker === worker
+ )
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
public setWorkerChoiceStrategy (
- workerChoiceStrategy: WorkerChoiceStrategy
+ workerChoiceStrategy: WorkerChoiceStrategy,
+ workerChoiceStrategyOptions?: WorkerChoiceStrategyOptions
): void {
+ this.checkValidWorkerChoiceStrategy(workerChoiceStrategy)
this.opts.workerChoiceStrategy = workerChoiceStrategy
- for (const [index, workerItem] of this.workers.entries()) {
- this.setWorker(index, workerItem.worker, {
+ for (const workerNode of this.workerNodes) {
+ this.setWorkerNodeTasksUsage(workerNode, {
run: 0,
running: 0,
runTime: 0,
+ runTimeHistory: new CircularArray(),
avgRunTime: 0,
+ medRunTime: 0,
error: 0
})
}
this.workerChoiceStrategyContext.setWorkerChoiceStrategy(
- this,
- workerChoiceStrategy
+ this.opts.workerChoiceStrategy
)
+ if (workerChoiceStrategyOptions != null) {
+ this.setWorkerChoiceStrategyOptions(workerChoiceStrategyOptions)
+ }
}
- /** {@inheritDoc} */
- public abstract get full (): boolean
+ /** @inheritDoc */
+ public setWorkerChoiceStrategyOptions (
+ workerChoiceStrategyOptions: WorkerChoiceStrategyOptions
+ ): void {
+ this.opts.workerChoiceStrategyOptions = workerChoiceStrategyOptions
+ this.workerChoiceStrategyContext.setOptions(
+ this.opts.workerChoiceStrategyOptions
+ )
+ }
- /** {@inheritDoc} */
- public abstract get busy (): boolean
+ /** @inheritDoc */
+ public enableTasksQueue (
+ enable: boolean,
+ tasksQueueOptions?: TasksQueueOptions
+ ): void {
+ if (this.opts.enableTasksQueue === true && !enable) {
+ for (const [workerNodeKey] of this.workerNodes.entries()) {
+ this.flushTasksQueue(workerNodeKey)
+ }
+ }
+ this.opts.enableTasksQueue = enable
+ this.setTasksQueueOptions(tasksQueueOptions as TasksQueueOptions)
+ }
+
+ /** @inheritDoc */
+ public setTasksQueueOptions (tasksQueueOptions: TasksQueueOptions): void {
+ if (this.opts.enableTasksQueue === true) {
+ this.checkValidTasksQueueOptions(tasksQueueOptions)
+ this.opts.tasksQueueOptions =
+ this.buildTasksQueueOptions(tasksQueueOptions)
+ } else {
+ delete this.opts.tasksQueueOptions
+ }
+ }
+
+ private buildTasksQueueOptions (
+ tasksQueueOptions: TasksQueueOptions
+ ): TasksQueueOptions {
+ return {
+ concurrency: tasksQueueOptions?.concurrency ?? 1
+ }
+ }
+
+ /**
+ * Whether the pool is full or not.
+ *
+ * The pool filling boolean status.
+ */
+ protected abstract get full (): boolean
+
+ /**
+ * Whether the pool is busy or not.
+ *
+ * The pool busyness boolean status.
+ */
+ protected abstract get busy (): boolean
protected internalBusy (): boolean {
- return (
- this.numberOfRunningTasks >= this.numberOfWorkers &&
- this.findFreeWorkerKey() === -1
- )
+ return this.findFreeWorkerNodeKey() === -1
}
- /** {@inheritDoc} */
- public findFreeWorkerKey (): number {
- return this.workers.findIndex(workerItem => {
- return workerItem.tasksUsage.running === 0
+ /** @inheritDoc */
+ public findFreeWorkerNodeKey (): number {
+ return this.workerNodes.findIndex(workerNode => {
+ return workerNode.tasksUsage?.running === 0
})
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
public async execute (data: Data): Promise<Response> {
- const [workerKey, worker] = this.chooseWorker()
- const messageId = crypto.randomUUID()
- const res = this.internalExecute(workerKey, worker, messageId)
- this.checkAndEmitBusy()
- this.sendToWorker(worker, {
+ const [workerNodeKey, workerNode] = this.chooseWorkerNode()
+ const submittedTask: Task<Data> = {
// eslint-disable-next-line @typescript-eslint/consistent-type-assertions
data: data ?? ({} as Data),
- id: messageId
+ id: crypto.randomUUID()
+ }
+ const res = new Promise<Response>((resolve, reject) => {
+ this.promiseResponseMap.set(submittedTask.id as string, {
+ resolve,
+ reject,
+ worker: workerNode.worker
+ })
})
+ if (
+ this.opts.enableTasksQueue === true &&
+ (this.busy ||
+ this.workerNodes[workerNodeKey].tasksUsage.running >=
+ ((this.opts.tasksQueueOptions as TasksQueueOptions)
+ .concurrency as number))
+ ) {
+ this.enqueueTask(workerNodeKey, submittedTask)
+ } else {
+ this.executeTask(workerNodeKey, submittedTask)
+ }
+ this.checkAndEmitEvents()
// eslint-disable-next-line @typescript-eslint/return-await
return res
}
- /** {@inheritDoc} */
+ /** @inheritDoc */
public async destroy (): Promise<void> {
await Promise.all(
- this.workers.map(async workerItem => {
- await this.destroyWorker(workerItem.worker)
+ this.workerNodes.map(async (workerNode, workerNodeKey) => {
+ this.flushTasksQueue(workerNodeKey)
+ await this.destroyWorker(workerNode.worker)
})
)
}
/**
- * Shutdowns given worker.
+ * Shutdowns the given worker.
*
- * @param worker - A worker within `workers`.
+ * @param worker - A worker within `workerNodes`.
*/
protected abstract destroyWorker (worker: Worker): void | Promise<void>
/**
- * Setup hook that can be overridden by a Poolifier pool implementation
- * to run code before workers are created in the abstract constructor.
+ * Setup hook to execute code before worker node are created in the abstract constructor.
+ * Can be overridden
+ *
+ * @virtual
*/
protected setupHook (): void {
- // Can be overridden
+ // Intentionally empty
}
/**
protected abstract isMain (): boolean
/**
- * Hook executed before the worker task promise resolution.
+ * Hook executed before the worker task execution.
* Can be overridden.
*
- * @param workerKey - The worker key.
+ * @param workerNodeKey - The worker node key.
*/
- protected beforePromiseResponseHook (workerKey: number): void {
- ++this.workers[workerKey].tasksUsage.running
+ protected beforeTaskExecutionHook (workerNodeKey: number): void {
+ ++this.workerNodes[workerNodeKey].tasksUsage.running
}
/**
- * Hook executed after the worker task promise resolution.
+ * Hook executed after the worker task execution.
* Can be overridden.
*
* @param worker - The worker.
* @param message - The received message.
*/
- protected afterPromiseResponseHook (
+ protected afterTaskExecutionHook (
worker: Worker,
message: MessageValue<Response>
): void {
++workerTasksUsage.error
}
if (this.workerChoiceStrategyContext.getRequiredStatistics().runTime) {
- workerTasksUsage.runTime += message.taskRunTime ?? 0
+ workerTasksUsage.runTime += message.runTime ?? 0
if (
this.workerChoiceStrategyContext.getRequiredStatistics().avgRunTime &&
workerTasksUsage.run !== 0
workerTasksUsage.avgRunTime =
workerTasksUsage.runTime / workerTasksUsage.run
}
+ if (this.workerChoiceStrategyContext.getRequiredStatistics().medRunTime) {
+ workerTasksUsage.runTimeHistory.push(message.runTime ?? 0)
+ workerTasksUsage.medRunTime = median(workerTasksUsage.runTimeHistory)
+ }
}
}
/**
- * Removes the given worker from the pool.
+ * Chooses a worker node for the next task.
*
- * @param worker - The worker that will be removed.
- */
- protected removeWorker (worker: Worker): void {
- const workerKey = this.getWorkerKey(worker)
- this.workers.splice(workerKey, 1)
- this.workerChoiceStrategyContext.remove(workerKey)
- }
-
- /**
- * Chooses a worker for the next task.
+ * The default uses a round robin algorithm to distribute the load.
*
- * The default implementation uses a round robin algorithm to distribute the load.
- *
- * @returns [worker key, worker].
+ * @returns [worker node key, worker node].
*/
- protected chooseWorker (): [number, Worker] {
- const workerKey = this.workerChoiceStrategyContext.execute()
- return [workerKey, this.workers[workerKey].worker]
+ protected chooseWorkerNode (): [number, WorkerNode<Worker, Data>] {
+ let workerNodeKey: number
+ if (this.type === PoolType.DYNAMIC && !this.full && this.internalBusy()) {
+ const workerCreated = this.createAndSetupWorker()
+ this.registerWorkerMessageListener(workerCreated, message => {
+ if (
+ isKillBehavior(KillBehaviors.HARD, message.kill) ||
+ (message.kill != null &&
+ this.getWorkerTasksUsage(workerCreated)?.running === 0)
+ ) {
+ // Kill message received from the worker: no new tasks are submitted to that worker for a while ( > maxInactiveTime)
+ this.flushTasksQueueByWorker(workerCreated)
+ void this.destroyWorker(workerCreated)
+ }
+ })
+ workerNodeKey = this.getWorkerNodeKey(workerCreated)
+ } else {
+ workerNodeKey = this.workerChoiceStrategyContext.execute()
+ }
+ return [workerNodeKey, this.workerNodes[workerNodeKey]]
}
/**
): void
/**
- * Registers a listener callback on a given worker.
+ * Registers a listener callback on the given worker.
*
* @param worker - The worker which should register a listener.
* @param listener - The message listener callback.
protected abstract createWorker (): Worker
/**
- * Function that can be hooked up when a worker has been newly created and moved to the workers registry.
+ * Function that can be hooked up when a worker has been newly created and moved to the pool worker nodes.
*
* Can be used to update the `maxListeners` or binding the `main-worker`\<-\>`worker` connection if not bind by default.
*
protected abstract afterWorkerSetup (worker: Worker): void
/**
- * Creates a new worker for this pool and sets it up completely.
+ * Creates a new worker and sets it up completely in the pool worker nodes.
*
* @returns New, completely set up worker.
*/
worker.on('online', this.opts.onlineHandler ?? EMPTY_FUNCTION)
worker.on('exit', this.opts.exitHandler ?? EMPTY_FUNCTION)
worker.once('exit', () => {
- this.removeWorker(worker)
+ this.removeWorkerNode(worker)
})
- this.pushWorker(worker, {
- run: 0,
- running: 0,
- runTime: 0,
- avgRunTime: 0,
- error: 0
- })
+ this.pushWorkerNode(worker)
this.afterWorkerSetup(worker)
}
/**
- * This function is the listener registered for each worker.
+ * This function is the listener registered for each worker message.
*
* @returns The listener function to execute when a message is received from a worker.
*/
protected workerListener (): (message: MessageValue<Response>) => void {
return message => {
- if (message.id !== undefined) {
+ if (message.id != null) {
+ // Task execution response received
const promiseResponse = this.promiseResponseMap.get(message.id)
- if (promiseResponse !== undefined) {
+ if (promiseResponse != null) {
if (message.error != null) {
promiseResponse.reject(message.error)
} else {
promiseResponse.resolve(message.data as Response)
}
- this.afterPromiseResponseHook(promiseResponse.worker, message)
+ this.afterTaskExecutionHook(promiseResponse.worker, message)
this.promiseResponseMap.delete(message.id)
+ const workerNodeKey = this.getWorkerNodeKey(promiseResponse.worker)
+ if (
+ this.opts.enableTasksQueue === true &&
+ this.tasksQueueSize(workerNodeKey) > 0
+ ) {
+ this.executeTask(
+ workerNodeKey,
+ this.dequeueTask(workerNodeKey) as Task<Data>
+ )
+ }
}
}
}
}
- private async internalExecute (
- workerKey: number,
- worker: Worker,
- messageId: string
- ): Promise<Response> {
- this.beforePromiseResponseHook(workerKey)
- return await new Promise<Response>((resolve, reject) => {
- this.promiseResponseMap.set(messageId, { resolve, reject, worker })
- })
+ private checkAndEmitEvents (): void {
+ if (this.opts.enableEvents === true) {
+ if (this.busy) {
+ this.emitter?.emit(PoolEvents.busy)
+ }
+ if (this.type === PoolType.DYNAMIC && this.full) {
+ this.emitter?.emit(PoolEvents.full)
+ }
+ }
}
- private checkAndEmitBusy (): void {
- if (this.opts.enableEvents === true && this.busy) {
- this.emitter?.emit('busy')
- }
+ /**
+ * Sets the given worker node its tasks usage in the pool.
+ *
+ * @param workerNode - The worker node.
+ * @param tasksUsage - The worker node tasks usage.
+ */
+ private setWorkerNodeTasksUsage (
+ workerNode: WorkerNode<Worker, Data>,
+ tasksUsage: TasksUsage
+ ): void {
+ workerNode.tasksUsage = tasksUsage
}
/**
- * Gets worker tasks usage.
+ * Gets the given worker its tasks usage in the pool.
*
* @param worker - The worker.
+ * @throws Error if the worker is not found in the pool worker nodes.
* @returns The worker tasks usage.
*/
private getWorkerTasksUsage (worker: Worker): TasksUsage | undefined {
- const workerKey = this.getWorkerKey(worker)
- if (workerKey !== -1) {
- return this.workers[workerKey].tasksUsage
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ if (workerNodeKey !== -1) {
+ return this.workerNodes[workerNodeKey].tasksUsage
}
- throw new Error('Worker could not be found in the pool')
+ throw new Error('Worker could not be found in the pool worker nodes')
}
/**
- * Pushes the given worker.
+ * Pushes the given worker in the pool worker nodes.
*
* @param worker - The worker.
- * @param tasksUsage - The worker tasks usage.
+ * @returns The worker nodes length.
*/
- private pushWorker (worker: Worker, tasksUsage: TasksUsage): void {
- this.workers.push({
+ private pushWorkerNode (worker: Worker): number {
+ return this.workerNodes.push({
worker,
- tasksUsage
+ tasksUsage: {
+ run: 0,
+ running: 0,
+ runTime: 0,
+ runTimeHistory: new CircularArray(),
+ avgRunTime: 0,
+ medRunTime: 0,
+ error: 0
+ },
+ tasksQueue: []
})
}
/**
- * Sets the given worker.
+ * Sets the given worker in the pool worker nodes.
*
- * @param workerKey - The worker key.
+ * @param workerNodeKey - The worker node key.
* @param worker - The worker.
* @param tasksUsage - The worker tasks usage.
+ * @param tasksQueue - The worker task queue.
*/
- private setWorker (
- workerKey: number,
+ private setWorkerNode (
+ workerNodeKey: number,
worker: Worker,
- tasksUsage: TasksUsage
+ tasksUsage: TasksUsage,
+ tasksQueue: Array<Task<Data>>
): void {
- this.workers[workerKey] = {
+ this.workerNodes[workerNodeKey] = {
worker,
- tasksUsage
+ tasksUsage,
+ tasksQueue
}
}
+
+ /**
+ * Removes the given worker from the pool worker nodes.
+ *
+ * @param worker - The worker.
+ */
+ private removeWorkerNode (worker: Worker): void {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ this.workerNodes.splice(workerNodeKey, 1)
+ this.workerChoiceStrategyContext.remove(workerNodeKey)
+ }
+
+ private executeTask (workerNodeKey: number, task: Task<Data>): void {
+ this.beforeTaskExecutionHook(workerNodeKey)
+ this.sendToWorker(this.workerNodes[workerNodeKey].worker, task)
+ }
+
+ private enqueueTask (workerNodeKey: number, task: Task<Data>): number {
+ return this.workerNodes[workerNodeKey].tasksQueue.push(task)
+ }
+
+ private dequeueTask (workerNodeKey: number): Task<Data> | undefined {
+ return this.workerNodes[workerNodeKey].tasksQueue.shift()
+ }
+
+ private tasksQueueSize (workerNodeKey: number): number {
+ return this.workerNodes[workerNodeKey].tasksQueue.length
+ }
+
+ private flushTasksQueue (workerNodeKey: number): void {
+ if (this.tasksQueueSize(workerNodeKey) > 0) {
+ for (const task of this.workerNodes[workerNodeKey].tasksQueue) {
+ this.executeTask(workerNodeKey, task)
+ }
+ }
+ }
+
+ private flushTasksQueueByWorker (worker: Worker): void {
+ const workerNodeKey = this.getWorkerNodeKey(worker)
+ this.flushTasksQueue(workerNodeKey)
+ }
}